The current El Nino is the strongest on record and is likely to continue until around May, but with its fallout - especially in South-east Asia - expected to be felt until the end of the year.
Dozens have died and millions of dollars have been lost due to El Nino-related weather, from storms and floods in the Americas to drought in South-east Asia.El Nino causes warm waters that normally pile up in the Western Pacific to flow east, triggering heavier rain along the west coast of the Americas and drier conditions in Australasia and South-east Asia.
Early warning systems have improved. That the current El Nino would be one of the strongest was suspected by early last year and confirmed by August. In mainland South-east Asia, a rainfall deficit led to farmers being warned of a water shortage in the coming dry season.
El Nino-triggered events can sometimes be welcome: rain and snow in California have broken a 10-year drought. Even hard times can have a silver lining for some - low sugar prices are rebounding as supply decreases, with El Nino denting sugar cane crop yields. Yet higher sugar prices are no comfort to the thousands forced to flee their homes as flood waters rise, as in recent weeks in South America.
In 1997-98, the strongest El Nino on record until then led to the deaths of 23,000 people from natural disasters, increased poverty rates by 15 per cent in some countries, and cost governments up to
US$45 billion (S$64 billion) due to severe storms, droughts and other effects, says the World Bank.
The erratic weather triggered by El Nino exacerbates vulnerabilities and exposes poor management of resources. These are critical as climate change can intensify the effects of periodic events like El Nino, turning adversity into disaster.
An El Nino year is a foretaste of the reality of a warming planet, with lessons learnt useful for worse to come as global warming poses an epochal challenge to our species.